Process of manufacturing metal bodies.



F. PAGHER. PROCESS OF MANUFACTURING METAL BODIES.

APPLICATION FILED DEO.5, 1911. v

Patented Apr. 7, 1911 2 SHEETS SHEET 1 F. PAC-HER. PROCESS OF MANUFACTURING METAL BODIES.

APPLICATION FILED DEUK5,1911,

Patented Apr. 7, 1914 2 SHEETS-SHEET 2.

I NT

I FRANZ PAGHER, OF DUSSELDOBF-RATH, GERMANY.

PROCESS OF MANUFACTURING METAL BODIES.

Specification oflLetter's Patent.

Patented Apr. t, 19114.

Application filed December 5, 1911. Serial No. 664,002.

particularly in a super-heated condition, ab-

sorb considerable quantities of oxids and gases. The attempt has been made to separate these gases and oxids from the metal by merely allowing the metal to cool or solidify, whereby" without doubt the con- .tent'of gases and oxids in the metal bath is partially or as completely as possible diminished. The known processes of this kind, however, have the disadvantage that they involve the de-oxidation and de-gasifying of the metal bath before the metal is finished in respect of its composition, that is to say before theproper additions preliminary to casting have been made, either for the purpose of completing the tie-oxidation or for achieving the desired composition of the metal considered as an alloy.

The present invention consists in allowing the metal, which has been melted in any usual manner and has been finished so far as its metallic composition is concerned and is therefore ready for casting, to cool or solidify once or several times before it is cast and then heating it again as quickly as possible but only a little above the solidifying temperature, and finally immediately casting the metal. Thus the invention differs from the cooling and solidifying operations which have hitherto been used for degasifying the metal in that it consists in a separate treatment subsequent to the usual .45 treatment for the manufacture 'ofthe, fin- Z ished metal and immediately before the lat- Q ter is cast- The result of the process according to the invention is that the" ases and oxids still present in the metal me e in the usual manner and ready for casting, are

7 for the most part separated during the coolingor solidifying operation, and in part by the. subsequent fusion; moreover, the formation of fresh oxide and the development of fresh gases in the metal bath are ex- .fireproof material.

cluded because between the cooling or solidification with the subsequent re-melting, and the casting of metal into the ingot molds no further addition is made, for the metal is finished in respect of its metallic constituents before the application of the invention. Moreover the heat applied in remelting and heating the metal for the purpose of casting it, raises the temperature only slightly above the melting point and in so short a time that fresh absorption of gases by the metal from the air and the products of combustion is excluded. The last named conditions, namely the re-heating temperature as low as possible and lying near the solidification point, which is at the same time the casting temperature, and immediate casting after this temperature has been attained,

are the essential characteristics of the invention.

In the accompanying drawing two apparatus suitable for applying the invention are shown.

F gure 1 is a vertical section and Fig. 2 a horizontal section through one apparatus. Figs. 3 and 4 are like views respectively of another apparatus. Fig. 5 is a view similar to Fig. 1 showing the transformer core in sect1on and the device located over a pit. Fig. 6 1s a horizontal section of Fig. 5.

The metal A is run from any suitable melting furnace into an annular container It constructed as a castin ladle and lined with v n this container the metal is cooled or is allowed to solidify, whereby the gases dissolved during the first melting operation are in large part evolved. The uniformity of the cooling or solidificatron of the metal at all parts thereof is achieved by the annular form of the container R which has" the same cross section throughout. The progress of the cooling is advantageously watched by observing a pyrometer suitably introduced. Next 01- lows the re-heating or re-melting of the metal for the purpose of separating gases still inclosed and for casting. In the case of a container of the... type shown in F gs. 1 and 2 this operation is most convenlently performed by mounting the container so that the inner wall of the annular vessel surrounds the magnetof a transformer as shown in Figs. 4 and 5. In Figs. 3 and 4 the container R is shown as permanently provided with a magnet core M and a pmmary winding S. In both cases the induction current is brought into action and the metal rc-heated or re-melted in the shortest possible time and at the lowest possible temper-Maire. Just as in the previous operation of cooling or solidifying the uniform cross section of the annular metal bath con- (luecs to uniform cooling or solidification, so in the re-heating or re-melting operation this uniform cross section conduces to a uniform heating in all parts of the metal rceording to the law which governs heating by electric induction. Since the reheating or re-melting is to be accomplished in the shortest possible time it is advantageous to make the annular container as narrow in cross section and as high as is practicable.

As the re-heating or re-melting occurs in the shortest possible time at the lowest possib'le temperature, and through a cross section as uniform as possible, no gases can be taken up by the metal, which is therefore free of gas when obtained in this manner, for the gases still remaining in the metal after the first fusion are separated during the :re-heating or re-melting and secondly the metal has no further opportunity to ab sorb fresh gases. The de-gasified metal is cast in the usual manner. In order, however, to insure a uniform casting temperature, particularly in the case of large quantities of metal, the electric current maybe maintained in action during the casting; in this case, in the use of the construction shown in Figs. 1 and 2, the casting pit W is arranged below the stationary transformer, as shown in Figs. 4L and 5, and it is suitable to use movable ingot molds. If the transportable form shown in Figs. 3 and 4: is used the casting can occur at any place where there is electric current.

The process can be carried out in any suitable melting furnace provided that the aforesaid conditions are attainable.

I claim herewith as my invention.

1. The herein described process of manufacturing metal bodies free from gas and blow holes consisting in first heating the metal to a molten state to a condition of finished metal; then allowing the metal to cool and solidify; then reheating the metal as quickly as possible to-a temperature only slightly above the solidifying point thereof, and then casting the metal.

2. The herein described process of manufacturing metal bodies free from gas and blow holes consisting in first heating the metal to a molten state to a condition of finished metal; then allowing the metal to cool and solidify into an annular body,

then reheating the metal as quieklyas possible to a temperature only slightly above the solidifying point thereof, and then casting the metal.

3. The herein described process of manufacturing metal bodies free from gas and blow holes consisting in first heating the metal to a molten state to a condition of finished metal; then allowing the metal to cool and solidify into an annular body; then While in the form of an annular body, and as quickly as possible, reheating the metal to a temperature only slightly above the solidfying point of the metal, such reheating being efl'ected by an agency enveloping the annular body, and then immediately casting the metal.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses. A

FRANZ PAGHER. Witnesses:

. LEONHARD UNKELBACH,

F. MtiLs'rRoH. 

